Concrete plants dispense concrete ingredients, mixed concrete, or both, either individually or combined, depending on their design. Different types of concrete plants satisfy different needs and are used according to a variety of conditions, including the availability of raw materials for concrete, where the concrete is to be used, how much concrete is needed, and environmental concerns, to name a few.
One type of concrete plant dispenses mainly admixtures used in concrete recipes. Admixtures are materials, other than cement, aggregate, fibers, fines, and water, used to make concrete. Admixtures may be added to a concrete batch before or during the mixing period and are used to alter the properties of the fluid concrete, the set concrete, or both. Common admixtures include retardants, accelerators, plasticizers, water reducers, air-entrainers, colorants, and shrinkage reducers. To ensure a high quality finished concrete, an admixture and its constituents should be accurately measured according to the concrete batch recipe, that is, relative to the measured amounts of the other ingredients constituting a batch of concrete.
Other types of concrete plants dispense dry materials such as aggregate, fines, and cement and the water and admixtures are added to the concrete at the job site. Yet other concrete plants dispense dry materials as well as water, admixtures, or both, for example, the materials may be deposited into a vehicle equipped with a mixer, or into a mixing chamber at the plant. Concrete plants of the various types may be stationary, designed to be moved relatively easily, or may be portable.
Concrete plants are typically integrated systems employing numerous components. Silos or bins are commonly used to store aggregate, fines, and cement. Tanks store water. Other tanks store premixed admixtures or admixture raw components (collectively “admixtures”) used for various concrete recipes. Conveyors, cranes, chutes, pipes and pumps, or other equipment is commonly used to fill the silos, bins, and tanks, as well as move concrete ingredients from their storage places to dispensing or mixing equipment. Measuring equipment is used to weigh or otherwise measure the amount of ingredients used for a concrete batch when the ingredients are moved from their storage places to dispensing or mixing equipment. Various hoses, pipes, valves, sensors, and sources of pressurized fluids are commonly used to move ingredients, operate pumps, and perform other tasks for a concrete plant.
Current Concrete Plant Operations
Concrete plant operators commonly design or receive building specifications for a batch of concrete. Building specifications may be standardized depending on the use for the concrete, or may be customized for particular concrete projects. Building specifications typically provide requirements for the properties of a batch of concrete, such as the minimum compressive strength when cured, the slump when wet, the amount of water permeability for the cured concrete, color, etc. Creating batches of concrete that meet the building specifications commonly requires a batch recipe calling for a mixture of ingredients including cement, aggregates, water, and admixtures. Using admixtures in a concrete batch recipe provides a wider range of properties, for both the wet concrete and the cured concrete, than using cement, aggregates, and water alone.
Meeting building specifications commonly requires a precise amount of admixtures to be added to a given ratio and amount of cements, such as Portland cement type I-IV, fly ash, and other cement materials, aggregates, and water. Therefore, companies that manufacture admixtures have developed application specific admixture recipes, where various admixture recipes are used with basic concrete recipes (that is, recipes for the amount of cements, aggregates, and water) to alter the properties of the basic concrete recipes to meet standardized building specifications, such as a department of transportation's building specification for concrete used for highway construction. Of course, meeting specialized building specifications requires developing a customized admixture recipe.
Using admixtures commonly requires complex calculations. Customized admixture recipes require accounting for the unique building specifications as well as the materials used to create the concrete. But, even application specific admixture recipes commonly need to be modified because of variables such as the temperature and moisture content of the materials used to make a batch of concrete, environmental factors such as temperature and humidity, and the type of materials available (such as the type or source of cements, or the type or source of aggregates) for making a batch of concrete. However, admixtures are commonly pre-mixed before delivery to a concrete plant and therefore admixtures are not typically modified.
To create a concrete batch meeting the requirements for a building specification, concrete plant operators commonly call or send an electronic message with the building specifications to an admixture company. Currently, admixture companies typically call or send an electronic message to the concrete plant providing the types and amounts of admixtures needed to meet the building specifications. Depending on the type of batch panel a concrete plant has, the concrete plant operator either inputs the admixture recipe into a batch panel computer, or operates the batch panel to dispense the types and amounts of admixtures in the recipe.
Existing batch panels include a range of electronic sophistication from logic circuits that generate continuous-time electrical signals to operate concrete plant equipment, to computerized systems employing antiquated, out-of-date computer systems, to modern computer systems. Existing batch panels therefore create a range of signals from continuous-time electrical signals, for example, signals having various frequencies, waveforms, or both, to digital signals including digital signal formats used by various computer systems.
Concrete plant operators use the batch panel to control concrete plant equipment to implement concrete recipes. For example, a batch panel with logic circuits is commonly used to implement a basic concrete recipe as well as an admixture recipe by the operator toggling various switches for amounts of time that depend on the concrete recipe being implemented. A batch panel with logic circuits typically provides little to no feedback regarding the operational status of the concrete plant equipment aside from a light or other sign that a switch is in an “on” position. Computerized batch panels commonly receive both a basic concrete recipe and an admixture recipe from the operator and the computer operates concrete plant equipment to dispense the materials, including admixtures (which are typically pre-mixed admixtures), needed to create the concrete recipe. Because of the computerization, such batch panels may receive limited feedback regarding the operational status of the concrete plant equipment, for example, the number of pulses from a flow meter. However, because there is typically one batch panel and numerous pieces of equipment, computerized batch panels currently require large amounts of wiring between the batch panel and the equipment. And, depending on the computer's capabilities, the amount of information the batch panel can handle may be limited. Intensive wiring, limited computing capability, or both, may limit the amount of control, monitoring, and feedback a batch panel can provide.